The objective of this research is to biochemically characterize the protein and nonprotein components of the adhesive formed by the sea mussel, Mytilus edulis. The hardened adhesive disc produced by this organism is extremely resistant to dissolution making its biochemical characterization very difficult. Thus, methods have been developed for isolating "soluble" precursors of the adhesive substance. Separation of the precursors has been previously demonstrated. In the proposed research program, these "soluble" protein adhesive components will be biochemically characterized for primary, secondary, and tertiary structure. The enzyme component will be characterized for activity and for kinetic properties and the mucoid component of the adhesive will be biochemically characterized. Isolated, purified adhesive components will then be combined under various environmental conditions, in vitro, to form adhesive products. Adhesive products will be biochemically and biophysically compared to the natural adhesive by determining characteristic cross-links and by measuring resistance to chemical degradation.